Recently we posted the following article commenting on the impact of USD appreciation and dollar circulation among oil exporters, as well as how the collapsing price of oil is set to reverberate across the entire oil-exporting world, where sticky high oil prices were a key reason for social stability. Following today's shocking OPEC announcement and the epic collapse in crude prices, it is time to repost it now that everyone is desperate to become a bear market oil expert, if only on Twitter...

The Petrodollar, long serving as the US leverage to encourage and facilitate USD recycling, and a steady reinvestment in US-denominated assets by the Oil exporting nations, and thus a means to steadily increase the nominal price of all USD-priced assets, just drove itself into irrelevance. A consequence of this year's dramatic drop in oil prices, the shift is likely to cause global market liquidity to fall. This decline follows years of windfalls for oil exporters such as Russia, Angola, Saudi Arabia and Nigeria. Much of that money found its way into financial markets, helping to boost asset prices and keep the cost of borrowing down, through so-called petrodollar recycling. But no more: "this year the oil producers will effectively import capital amounting to $7.6 billion.

In August 2013, the Nasdaq SIP broke and trading in Nasdaq stocks was halted for 3 hours. Yesterday, at 1:07 PM ET, the NYSE SIP broke but trading was allowed to continue until the backup facility was put on line. ?Apparently, the NYSE didn’t think it was necessary to halt trading in their listed stocks... despite customers not receiving accurate pricing.

A week ago, when we commented on the latest publicly available data for Barclays' fraud-embroiled LX dark pool, whose volume as we reported had tumbled 37% in the week of the lawsuit announcement, we said that the downward volume trend "is about to get a whole lot worse for Barclays as the trickle becomes an avalanche." Sure enough, following today's reported by Finra's ATS database for the week of June 30, we find just that, and one can largely say lights out to Barclays LX operation, whose total shares traded plummeted from 197 million (and 312 million the week before) to a paltry 66.4 million, a two-week drop of 79% from its recent highs, putting it, in 12th total dark pool volume place, below ITG and above BIDS trading. So much for any ambitions of becoming America's top dark pool. Last on the other hand...

In case there is still any confusion on whose behalf the US regulators work when they "fine" banks, the latest announcement from Finra should make it all clear. Recall the spectacle full of pomp and circumstance surrounding NY AG Scheinderman's demolition of Barclays after it was announced that the bank had lied to its customers to drive more traffic to Barclays LX, its dark pool, and allow HFT algos to frontrun buyside traffic. Yes, it was warranted, and the immediate result was the complete collapse in all buyside Barclays dark pool volume, meaning predatory HFT algos would have to find some other dark pool where to frontrun order flow. Such as Goldman's Sigma X. Which brings us to, well, Goldman's Sigma X, which moments ago, in a far less pompous presentation, was fined - not by the AG, not by the SEC, but by lowly Finra - for "Failing to Prevent Trade-Throughs in its Alternative Trading System." The impact: "In connection with the approximately 395,000 trade-throughs, Goldman Sachs returned $1.67 million to disadvantaged customers." The punchline, or rather, the "fine": $800,000.

Ever since Goldman's anti-HFT Op-Ed less than a month ago, and since the even more recent full-hearted support by Goldman of Michael Lewis' most recent entry into the anti-HFT crusade (one promoting the Goldman-supported IEX exchange), one thing has been clear: the days of market structure in its current format are numbered. This was further confirmed after Goldman exited both its legacy Spear Leeds & Kellogg designated market making post at the NYSE, and is said to be winding down its market-dominating dark pool, Sigma X. Sure enough, Post reports that just three weeks after the Gary Cohn Op-Ed, the SEC is "preparing to remove some high-frequency trading firms."

Back on March 21, before the release of Michael Lewis' Flash Boys and before the infamous 60 Minutes interview, when Goldman COO Gary Cohn wrote his infamous WSJ Op-ed bashing HFT, it was clear that something was afoot. That something became promptly clear when it was revealed that Goldman is among the core backers of the pseudo dark-pool IEX exchange popularized as the protagonist in Flash Boys, and juxtaposed to the frontrunning, and faceless, HFT antagonist that Lewis maanged to demonize so well in the span of a few hundred pages, he promptly provoked a renewed investigation by the FBI, the SEC and DOJ into HFT. A few days later, the shocker became a double whammy when Goldman announced that in addition to turning its back on HFT which had served it so well for years, the firm would also say goodbye to the NYSE and its designated market maker post, the last remaining legacy of its $6.5 billion Spear Ledds & Kellogg acquisition from 2000. Moments ago we got the third and final "shocker" in this series of stunning disclosures by Goldman, this time involving Goldman's own "unlit" venue - one involving its own Dark Pool - the infamous, and market dominant Sigma X, which according to the WSJ, is about to be shut down!

In what is a true double whammy of market structure stunners from Goldman over the past week, not only has the firm done an about face on HFT (we eagerly await Goldman's pardon of "HFT market manipulator" and former Goldman employee Sergey Aleynikov) and is now actively bashing the high freaks (much to the chagrin of Virtu and its pulled IPO, whose lead underwriter Goldman just happened to be), overnight it was reported that Goldman is also in the process of selling its "designated market-maker" unit to Dutch firm IMC Financial Markets to sell the trading business.

We know what you're thinking... why didn't Virtu Financial's CEO Chris Concannon ban Twitter and YouTube? It seems that is the only thing the HFT firm is incapable of as just too much public scrutiny from various fact-full blogs and a major expose of the reality of the US stock 'market' was too much for even the greatest fools in the market to be fooled by:

*VIRTU SAID TO DELAY IPO AMID FUROR OVER MICHAEL LEWIS BOOK

As we warned previously, it was only a matter of time before the hubris of VRTU's own trading perfection swung around and crushed it: "Simply put, first it was their boastful trading record that got the NYAG involved, and then Lewis slammed the door shut."

First of all, let's get one thing straight: if instead of about to breach a 20-handle, the Facebook stock price was in the $60, nobody would care about anything that happened in the past 3 days, everyone would be happy and delighted, and increasing the velocity of money with the comfort that some greater fool would be willing to pay even more for ridiculous overvalued ponzi, pardon, portfolio holdings. Alas, we are not there, and as a result, the fingerpointing phase has come and gone. Now come the lawsuits, because people, led to believe in huge short-term profits, are now faced to face with a grim sur-reality in which the tooth fairy was just exposed as the cookie monster. And the latest farcical development: Nasdaq finally pulling market conditions, but not just any market conditions - retroactive ones.

Last Wednesday we put up the following blurb: "Five months ago, when Italian yields were still tame in the 3% ballpark, and not 7% where they are today, we suggested that based on trading patterns and overall volume in Goldman's dark pool, Italy may be about to experience a "Greek episode." Days later we were proven right as Italian yields and spreads started their relentless move wider, with only those who had access to Sigma X being able to get an advance whiff of what was about to happen. Well today we are happy to report that the German diversion may have worked: the truth is that nobody appears to care about Germany. Instead what everyone does seem to care about, is the nation with the greatest combined debt (government, corporate and household) to GDP in the world. Yup. The UK." Following that, a quick Twitter update from this morning indicated something was again going on with the UK from the perspective of the world's most connected insiders: "UK's LLOYDS and RBS top of most active on Sigma X this morning." Sure enough, here's Fitch with what may well be a precursor to the bond vigilantes finally focusing their attention on the last, latest and greatest AAA credit.

FITCH: UK GOVT MAY BE MOST INDEBTED OF AAA SOVEREIGNS EX U.S. -BBG

FITCH: NEW UK FISCAL VIEWS 'SIGNIFICANT DETERIORATION' VS MARCH - BBG

And the punchline: "the capacity of UK public finances to absorb adverse economic and financial shocks that would result in yet higher public debt while retaining its 'AAA' status has largely been exhausted"

And cue the imminent downgrade rumors - and ensuing safe-haven outflows to TSYs.